Sun tracking mechanism

ABSTRACT

A sun tracking mechanism is provided for solar power generation, including a power unit, a linear actuator and at least two universal joints. The sun tracking mechanism outputs an angle of high precision by two axial directions provided from the universal joints, the power unit and the linear actuator. A solar power module disposed on the sun tracking mechanism generates electricity in the best light incident angle. In addition, the linear actuator provides an auxiliary supporting force to improve the wind-resistant capability.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to sun tracking mechanisms, and, more particularly, to a sun tracking mechanism for solar power generation.

2. Description of Related Art

With the rapid development of technology, demands for power grow steadily. Solar power is becoming one of the most indispensable power sources. A modern solar power module has a power conversion efficiency greatly increased. However, the location and light incident angle of the Sun is not always unchangeable. Thus, a sun tracking mechanism to which a solar power module is mounted is evolved from a fixed mode to an adjustable mode. The adjustable sun tracking mechanism employs a motor to adjust a tilted angle or deflected angle of a solar panel. Therefore, the solar panel tracks the Sun constantly, and the solar power module absorbs the sunlight at a best light incident angle and achieve a best power conversion efficiency.

However, the modern adjustable sun tracking mechanism is complicated and hard to be assembled, and has a high manufacturing cost. Further, the whole sun tracking mechanism cannot operate normally if a single component malfunctions. The modern adjustable sun tracking mechanism comprises a solar power module board and a single-axis supporting pole. Because the solar power module board has a large windward surface and the single-axis supporting pole is not robust enough to stabilize the solar power module board, the modern adjustable sun tracking mechanism is easily to shake severely and be deformed when wind blows the windward surface. Therefore, the modern sun tracking mechanism has a precision of tracking the Sun reduced. Moreover, the sun tracking mechanism outputs small angles, since the single-axis supporting pole is restricted by a limited rotation angle.

Therefore, how to design a sun tracking mechanism for solar power generation that has fewer components, stronger wind-resistant capability, high precision and a low manufacturing cost, and outputs great angles, is one of the most urgent issues in the art.

SUMMARY OF THE INVENTION

In view of the above-mentioned problems of the prior art, it is an objective of the present invention to provide a sun tracking mechanism for solar power generation. Compared with the prior art, the sun tracking mechanism has few components, stronger wind-resistant capability, and greater output angles. Joints of multiple degrees of freedom make the sun tracking mechanism to act nimbly, achieve higher precision, have a lower manufacturing cost, and allow a solar power module to absorb sunlight at a best light incident angle constantly and achieve a best power generation efficiency.

To achieve the above-mentioned and other objectives, the present invention provides a sun tracking mechanism, comprising: a base; a first universal joint; a second universal joint; a pole having a fixing end fixed to the base and a connecting end connected to the first universal joint; a power unit disposed on the connecting end of the pole for providing a transmission force to the first universal joint; a linear actuator having a first end connected to the second universal joint and a second end connected to the base and switching between a stretching state and a contracted state; and a plate having a first surface pivotally connected to the first universal joint and the second universal joint and a second surface, wherein the first universal joint allows the plate to rotate around a first axial direction and/or a second axial direction, wherein the plate rotates around the first axial direction with the first universal joint as a pivot when the power unit provides the transmission force to the first universal joint, and rotates around the second axial direction with the first universal joint as the pivot when the linear actuator is switching between the stretching state and the contracted state.

The sun tracking mechanism according to the present invention, through the power unit, the linear actuator and the first axial direction and the second axial direction provided by the first universal joint, outputs great angles. The joints of multiple degrees of freedom, i.e., the first universal joint and the second universal joint, allow the sun tracking mechanism to act nimbly, improve the angle precision, and facilitate a solar power module disposed on a sun tracking module to absorb sunlight at a best light incident angle constantly and have a best solar power generation efficiency. In addition to the supporting force provided from the pole, the linear actuator of the sun tracking mechanism according to the present invention further provides an auxiliary supporting force, which provides the sun tracking mechanism with improved wind-resistant capability and reduces the possibility that the sun tracking mechanism is deformed. Therefore, the sun tracking mechanism according to the present invention has its sun tracking precision been unaffected and a low manufacturing cost.

BRIEF DESCRIPTION OF DRAWINGS

The invention can be more fully understood by reading the following detailed description of the preferred embodiments, with reference made to the accompanying drawings, wherein:

FIG. 1 is a schematic diagram of a sun tracking mechanism according to the present invention;

FIG. 2 is a locally enlarged view of the sun tracking mechanism shown in FIG. 1;

FIG. 3 is a schematic connection view of a first universal joint and a power unit of the sun tracking mechanism shown in FIG. 1;

FIG. 4 is a schematic connection view of a second universal joint, a third universal joint and a linear actuator of the sun tracking mechanism shown in FIG. 1;

FIG. 5 is a schematic view of the sun tracking mechanism shown in FIG. 1 when operating in a first axial direction; and

FIG. 6 is a schematic view of the sun tracking mechanism shown in FIG. 1 when operating in a second axial direction.

DETAILED DESCRIPTION OF THE INVENTION

The following illustrative embodiments are provided to illustrate the disclosure of the present invention, these and other advantages and effects can be apparently understood by those in the art after reading the disclosure of this specification. The present invention can also be performed or applied by other different embodiments. The details of the specification may be on the basis of different points and applications, and numerous modifications and variations can be devised without departing from the spirit of the present invention.

Referring to FIGS. 1 and 2, a sun tracking mechanism 1 according to the present invention comprises a base 10, a first universal joint 11, a second universal joint 12, a pole 13, a power unit 14, a linear actuator 15 and a plate 16. The pole 13 has a connecting end 131 connected to the first universal joint 11 and a fixing end 132 fixed to the base 10. The power unit 14 is disposed on the pole 13. In an embodiment, the power unit 14 is disposed on the connecting end 131 of the pole 13 and around the first universal joint 11. In other words, both the power unit 14 and the first universal joint 11 are disposed on the connecting end 131 of the pole 13. Therefore, the power unit 14 can provide a transmission force to the first universal joint 11 easily. Of course, the power unit 14 can be disposed on other positions of the pole 13, as long as the transmission force generated by the power unit 14 can be provided to the first universal joint 11. In an embodiment, the power unit 14 is a servo motor, a stepping motor or a linear motor.

The linear actuator 15 has a first end 151 connected to the second universal joint 12 and a second end 152 connected to the base 10. In an embodiment, the linear actuator 15 has a variety of components, such as a driving motor, a reduction gear, a pushing rod, a screw rod, a slide base and a spring. Through these components, the linear actuator 15 transforms a rotation movement of the driving motor into a linear motion of the pushing rod, and drives the pushing rod to move back and forth along an axis through forward and backward rotating movements of the driving motor. Therefore, the pushing rod can operate in a stretching state by stretching itself to a region outside of the linear actuator 15, or in a contracted state by contracting itself back to the linear actuator 15. The switching mechanism between the stretching state and the contracted state is a back-and-forth linear motion that the linear actuator 15 and the pushing rod disposed therein can achieve.

The plate 16 has a first surface 161 pivotally connected to the first universal joint 11 and the second universal joint 12 and a second surface 162 having a solar power module 17 disposed thereon. In an embodiment, the first universal joint 11 is pivotally connected to a central point of the first surface 161 of the plate 16, and the second universal joint 12 is pivotally connected to a position of the first surface 161 of the plate 16 spaced from the central point at a distance.

In an embodiment according to the present invention, the first universal joint 11 provides a first axial direction and a second axial direction in which a member can rotate around. Refer to FIGS. 2 and 3. The first universal joint 11 comprises a first socket 113, a second socket 114 and a cross shaft 116. The first socket 113 is connected to the connecting end 131 of the pole 13. The second socket 114 is pivotally connected to the first surface 161 of the plate 16. The first socket 113 has two openings 115 for two opposing shaft ends 1161 and 1162 of the cross shaft 116 to be disposed therein. The second socket 114 also has two openings 115 for another two opposing shaft ends 1163 and 1164 of the cross shaft 116 to be disposed therein. Therefore, a relative motion between the first socket 113 and the second socket 114 allows the first socket 113 or the second socket 114 and the cross shaft 116 as a whole to rotate around a first axial direction 111 formed by the shaft ends 1161 and 1162. The first universal joint 11 provides the first axial direction 111 in which a member can rotate around, through the rotation of the shaft ends 1161 and 1162 of the cross shaft 116 in the two openings 115 of the first socket 113. Similarly, the second socket 114 or the first socket 113 and the cross shaft 116 as a whole can rotate around a second axial direction 112 formed by the shaft ends 1163 and 1164. The first universal joint 11 provides the second axial direction 112 in which a member can rotate around, through the rotation of the shaft ends 1163 and 1164 of the cross shaft 116 in the two openings 115 of the second socket 114.

The power unit 14 outputs the transmission force to the cross shaft 116 of the first universal joint 11 directly by engaging gears or coupling a transmission axle of the power unit 14 to any one of the shaft ends 1161, 1162, 1163 and 1164 of the cross shaft 116. In an embodiment according to the present invention, the transmission force of the power unit 14 is transmitted by a gear set. The power unit 14 has a first gear 141 disposed thereon. The cross shaft 116 has a second gear 142 disposed on the shaft end 1161 along the first axial direction 111. In order form the transmission force of the power unit 14 to be transmitted to the first universal joint 11, the first gear 141 and the second gear 142 have to be engaged. Therefore, the power unit 14 can transmit the transmission force to the cross shaft 116 through the engagement of the first gear 141 and the second gear 142, and the cross shaft 116 can acquire a force that it needs to rotate around the first axial direction 111. A gear ratio and gear distance between the first gear 141 and the second gear 142 can be adjusted according to an output power of the power unit 14. In an embodiment, the first gear 141 and the second gear 142 include a combination of a spur gear, a helical gear, a double helical gear, a bevel gear and a worm gear.

When the power unit 14 provides the transmission force to the first universal joint 11, the cross shaft 116 disposed on the first socket 113 can rotate around the first axial direction 111 and drive the second socket 114 to also rotate around the first axial direction 111, and the plate 16 pivotally connected to the second socket 114 of the first universal joint 11 moves accordingly. Therefore, the plate 16 rotates around the first axial direction 111 directly, with an axial center of the shaft ends 1161 and 1162 of the cross shaft 116 in the first universal joint 11 as a pivot. Please also refer to FIG. 5. FIG. 5 illustrates the plate 16 when rotating around the first axial direction 111. When the linear actuator 15 is switching between the stretching state and the contracted state, the power generated as the linear actuator 15 and the pushing rod disposed therein move back and forth along a line drives the plate 16 to rotate around the second axial direction 112, with a distance between the central point of the first surface 161 and the location where the second universal joint 12 is disposed on the first surface 161 of the plate 16 as a torque and an axial center of the shaft ends 1163 and 1164 of the cross shaft 116 in the first universal joint 11 as a pivot. Please refer to FIG. 6, which illustrates the plate 16 when rotating around the second axial direction 112.

In an embodiment, the first universal joint 11 is pivotally connected via a first pivot member 18 to the plate 16. As shown in FIG. 2, the first pivot member 18 passes through the second socket 114 such that the second socket 114 props against the plate 16. In an embodiment, the first pivot member 18 is a cylinder. The first pivot member 18 does not fix the second socket 114 to the plate 16, and the second socket 114 can rotate on the plate 16 through the first pivot member 18. In other words, the first pivot member 18 allows the second socket 114 to rotate, with respect to the plate 16, around a third axial direction 181. Therefore, the first universal joint 11 provides a three dimensional degree of freedom, including the first axial direction 111, the second axial direction 112 and the third axial direction 181, in which the first axial direction 111 is perpendicular to the second axial direction 112 and the third axial direction 181 is perpendicular to the first axial direction 111 or to the second axial direction 112.

In an embodiment, the second universal joint can also provide a fourth axial direction and a fifth axial direction in which a member can rotate around. Please refer to

FIGS. 1 and 4. The second universal joint 12 further comprises a third socket 121 connected to the first end 151 of the linear actuator 15, a fourth socket 122 pivotally connected to the first surface 161 of the plate 16, and a cross shaft 124. The third socket 121 comprises two openings 123 for two opposing shaft ends 1241 and 1242 of the cross shaft 124 to be disposed therein. The fourth socket 122 also has two openings 123 for another two opposing shaft ends 1243 and 1244 of the cross shaft 124 to be disposed therein. Therefore, a relative motion between the third socket 121 and the fourth socket 122 allows the third socket 121 or the fourth socket 122 and the cross shaft 124 as a whole to rotate around the fourth axial direction 125. In other words, the second universal joint 12 provides the fourth axial direction 125 in which a member can rotate around, through the rotation of the shaft ends 1241 and 1242 of the cross shaft 124 in the two openings 123 of the third socket 121. Similarly, the fourth socket 122 or the third socket 121 and the cross shaft 124 as a whole can rotate around the fifth axial direction 126 formed by the shaft ends 1243 and 1244. In other words, the second universal joint 12 provides the fifth axial direction 126 in which a member can rotate around, through the rotation of the shaft ends 1243 and 1244 of the cross shaft 124 in the two openings 123 of the fourth socket 122.

In an embodiment, the second universal joint 12 is pivotally connected via a second pivot member 19 to the plate 16. As shown in FIG. 2, the second pivot member 19 passes through the fourth socket 122, and the fourth socket 122 props against the plate 16. In an embodiment, the second pivot member 19 is a cylinder. The second pivot member 19 does not fix the fourth socket 122 to the plate 16, and the fourth socket 122 can rotate on the plate 16 through the second pivot member 19. In other words, the second pivot member 19 allows the plate 16 to rotate around the sixth axial direction 191. Therefore, the second universal joint 12 provides a three dimensional degree of freedom, including the fourth axial direction 125, the fifth axial direction 126 and the sixth axial direction 191, any two of which are perpendicular to each other. In an embodiment, the fourth axial direction 125, the fifth axial direction 126 and the sixth axial direction 191 are the same as the first axial direction 111, the second axial direction 112 and the third axial direction 181, respectively.

The first universal joint 11 and the second universal joint 12 according to the present invention provide the three dimensional degree of freedom through the adoption of the cross shaft and pivotal members. In an embodiment, the first universal joint 11 and the second universal joint 12 are a ball joint. After the first universal joint 11 rotates around the first axial direction 111 and the plate 16 is tilted at a certain angle, if the linear actuator 15 drives the plate 16 to rotate around the second axial direction 112, the second universal joint 12 also has to rotate around the fourth axial direction 125 or the fifth axial direction 126. Since further having the third axial direction 181 and the sixth axial direction 191, the first universal joint 11 and the second universal joint 12 can thus provide a greater angle output, an angle adjustment of high precision, and a greater degree of freedom.

In an embodiment, the second end 152 of the linear actuator 15 is fixed to the base 10 directly, or through a third universal joint 20 to the base 10 indirectly. The third universal joint 20 comprises a fifth socket 201 fixed to the second end 152 of the linear actuator, a sixth socket 202 fixed to the base 10, and a cross shaft 204. The fifth socket 201 has two openings 203 for two opposing shaft ends 2041 and 2042 of the cross shaft 204 to be disposed therein. The sixth socket 202 also has two openings 203 for another two opposing shaft ends 2043 and 2044 of the cross shaft 204 to be disposed therein. Therefore, a relative motion between the fifth socket 201 and the sixth socket 202 allows the fifth socket 201 or the sixth socket 202 and the cross shaft 204 to rotate around the fourth axial direction 205 formed by the shaft ends 2041 and 2042. In other words, the third universal joint 20 provides the fourth axial direction 205 in which a member can rotate around, through the rotation of the shaft ends 2041 and 2042 of the cross shaft 204 in the openings 203 of the fifth socket 201. Similarly, the sixth socket 202 or the fifth socket 201 and the cross shaft 204 as a whole can rotate around the fifth axial direction 206 formed by the shaft ends 2043 and 2044. In other words, the third universal joint 20 provides the fifth axial direction 206 in which a member can rotate around, through the rotation of the shaft ends 2043 and 2044 of the cross shaft 204 in the openings 203 of the sixth socket 202.

According to the sun tracking mechanism of the present invention, a power unit, a linear actuator, and a first universal joint and a second universal joint that have a multiple degree of freedom allow the sun tracking mechanism to act nimbly, output a great angle, improve the angle precision, and facilitate a solar power module disposed on a sun tracking module to absorb sunlight at a best light incident angle constantly and have a best solar power generation efficiency. According to the sun tracking mechanism, a linear actuator provides an auxiliary supporting force, which provides the sun tracking mechanism with improved wind-resistant capability and reduces the possibility that the sun tracking mechanism is deformed. Therefore, the sun tracking mechanism according to the present invention has its sun tracking precision been unaffected and a low manufacturing cost.

The foregoing descriptions of the detailed embodiments are only illustrated to disclose the features and functions of the present invention and not restrictive of the scope of the present invention. It should be understood to those in the art that all modifications and variations according to the spirit and principle in the disclosure of the present invention should fall within the scope of the appended claims. 

What is claimed is:
 1. A sun tracking mechanism, comprising: a base; a first universal joint; a second universal joint; a pole having a fixing end fixed to the base and a connecting end connected to the first universal joint; a power unit disposed on the connecting end of the pole for providing a transmission force to the first universal joint; a linear actuator having a first end connected to the second universal joint and a second end connected to the base and being switched between a stretching state and a contracted state; and a plate having a first surface pivotally connected to the first universal joint and the second universal joint and a second surface opposing the first surface, wherein the first universal joint allows the plate to rotate around a first axial direction and/or a second axial direction, wherein the plate rotates around the first axial direction with the first universal joint as a pivot when the power unit provides the transmission force to the first universal joint, and rotates around the second axial direction with the first universal joint as the pivot when the linear actuator is switched between the stretching state and the contracted state.
 2. The sun tracking mechanism of claim 1, wherein the first universal joint further comprises: a first socket connected to the connecting end of the pole and having two openings; a second socket pivotally connected to the first surface of the plate and having two openings; and a cross shaft having four shaft ends wherein, two opposing ones of which are disposed in the openings of the first socket to allow the first universal joint to rotate around the first axial direction through a relative motion between the cross shaft and the first socket, and the others of which are disposed in the openings of the second socket to allow the first universal joint to rotate around the second axial direction through a relative motion between the cross shaft and the second socket.
 3. The sun tracking mechanism of claim 2, further comprising a first pivot member passing through the second socket such that the second socket props against the plate, and the second socket rotates around a third axial direction through the first pivot member when a relative motion is performed between the second socket and the plate.
 4. The sun tracking mechanism of claim 3, wherein the power unit has a first gear disposed thereon, one of the shaft ends of the cross shaft along the first axial direction has a second gear disposed thereon, and the first gear and the second gear are engaged to transmit the transmission force of the power unit to the cross shaft, for providing a force needed by the cross shaft to rotate around the first axial direction.
 5. The sun tracking mechanism of claim 1, wherein the second universal joint further comprises: a third socket connected to the first end of the linear actuator and having two openings; a fourth socket pivotally connected to the first surface of the plate and having two openings; and a cross shaft having four shaft ends, wherein two opposing ones of which are disposed in the openings of the third socket to allow the second universal joint to rotate around a fourth axial direction through a relative motion between the cross shaft and the third socket, and the others of which are disposed in the openings of the fourth socket to allow the second universal joint to rotate around a fifth axial direction through a relation motion between the cross shaft and the fourth socket.
 6. The sun tracking mechanism of claim 5, further comprising a second pivot member passing through the fourth socket such that the fourth socket props against the plate, and the fourth socket rotates around a sixth axial direction through the second pivot member when a relative motion is performed between the fourth socket and the plate, wherein when the plate rotates around the first axial direction or the second axial direction, the second universal joint, by rotating itself around the fourth axial direction, the fifth axial direction or the sixth axial direction, provides a degree of freedom needed by the second universal joint to move in accordance with the plate.
 7. The sun tracking mechanism of claim 5, further comprising a third universal joint disposed between the linear actuator and the base, the third universal joint comprising: a fifth socket fixed to the second end of the linear actuator and having two openings; a sixth socket fixed to the base and having two openings; and a cross shaft having four shaft ends, two opposing ones of which are disposed in the openings of the fifth socket to allow the third universal joint to rotate around the fourth axial direction through a relative motion between the cross shaft and the fifth socket, and the others of which are disposed in the openings of the sixth socket to allow the third universal joint to rotate around the fifth axial direction through a relative motion between the cross shaft and the sixth socket.
 8. The sun tracking mechanism of claim 1, wherein the power unit is a servo motor, a stepping motor or a linear motor, and the first universal joint or the second universal joint is a ball joint.
 9. The sun tracking mechanism of claim 1, wherein the power unit has a first gear disposed thereon, the first universal joint has a second gear disposed thereon, and the first gear and the second gear are engaged to transmit the transmission force of the power unit to the first universal joint, for providing a force needed by the first universal joint to rotate around the first axial direction.
 10. The sun tracking mechanism of claim 1, wherein the first universal joint is pivotally connected to a central point of the first surface of the plate. 